Biochemical studies on the functional role and conformation of ribosomal RNA, RNA-protein interactions in the ribosome, and the molecular components of peptidyl transferase. BIBLIOGRAPHIC REFERENCES: Moore, V.G., Atchison, R.E., Thomas, G., Moran, M. and Noller, H.F. Identification of a ribosomal protein essential for peptidyl transferase activity. Proc, Nat. Acad. Sci. USA 72, 844-848 (1975). Herr, W. and Noller, H.F. A fragment of S23 RNA containing a nucleotide sequence complementary to a region of S5 RNA. FEBS Letters 53, 2 (1975).